Pathology of the kidney allograft.

The kidney biopsy still represents the best approach to diagnose renal transplant complications. It is considered the gold standard in the diagnosis of rejection and non-rejection complications. Although invasive, it is a safe procedure with a very low complication rate. With adequate sampling, changes related to antibody-mediated rejection (ABMR) and T-cell mediated rejection (TCMR) can be identified. However, the pathologist needs to be aware of the many other complications, not related to rejection, that can affect the allograft function. Examples include viral infections, drug toxicity, systemic diseases such as hypertension and diabetes, and recurrent or de novo glomerulopathy, among others. In this article, we review the recent classification of pathology of the kidney allograft, with reference to recent consensus reached at the most recent Banff renal allograft classification meetings, and also highlight common non-rejection complications of the kidney transplant.

Sensitivity of multiparametric MRI and targeted biopsy for detection of adverse pathologies (Cribriform gleason pattern 4 and intraductal carcinoma): Correlation of detected and missed prostate cancer foci with whole mount histopathology.

PURPOSE: Accurate preoperative detection of prostate cancer (PCa) exhibiting "cribriform" morphology (intraductal carcinoma [IDC-P] or cribriform Gleason pattern 4 [CrP4]) is important as it is independently associated with a variety of adverse clinical outcomes. The sensitivity of multiparametric magnetic resonance imaging (mpMRI) in the detection of PCa exhibiting "cribriform" morphology remains controversial. MATERIALS AND METHODS: A total of 117 eligible men with prospectively reported mpMRI who underwent in-bore MRI targeted biopsy followed by whole-mount radical prostatectomy (RP) were analyzed for lesion-level imaging-pathology correlation. RESULTS: Of the 206 PCa foci at RP (117 index and 89 non-index), 74% (152/206) were detected by mpMRI. Of the 54 tumors missed by mpMRI, most were non-index (98%, 53/54), grade group (GG) 1 (68%, 37/54) or GG 2 (26%, 14/54), with a median size of 1.0 cm (range, 0.7-1.5 cm), and non-cribriform morphology (96%, 52/54). Cribriform morphology was detected in 26% (53/206) of all tumors, and although targeted biopsies identified 96% (51/53) of these cancers, the cribriform component was depicted in only 45% (24/53). Of these, mpMRI detected all (100%, 44/44) index and 78% (7/9) of the non-index tumors. At univariable analysis, tumor size greater than 5 mm, % pattern 4 > 5%, cribriform morphology, zone (transition versus peripheral zone), and region (apex versus mid/base) were significantly associated with tumor visibility at mpMRI. At multivariable analysis, only tumor size, presence of any pattern 4, and peripheral zone remained significant predictors for visibility by mpMRI. CONCLUSION: At a lesion level, mpMRI offers high sensitivity for the detection of cribriform morphologies, however, the cribriform component is frequently missed by targeted biopsies. The MRI visibility is significantly associated with larger tumor size, presence of Gleason pattern 4, and peripheral zone location.

A Review Leveraging a Rare and Unusual Case of Basal Cell Carcinoma of the Prostate.

Basal cell carcinoma (BCC) is a rare nonacinar variant of prostatic carcinoma. In spite of prostatic acinar adenocarcinoma being one of the most common carcinomas in prostate, <100 prostatic BCC cases have been reported to date. Adenoid cystic/cribriform histology has been described in varying proportions to occur in prostatic BCC and is reported to be associated with aggressive behavior and high risk of metastasis. Herein, we present a case of prostatic BCC with adenoid cystic morphology, comprehensively describe its immunohistochemical and MYB/MYBL1 gene rearrangement findings, discuss its differential diagnosis, and review the literature of this rare entity.

Clinical Applications for Immunohistochemistry of Breast Lesions.

Immunohistochemical analysis has been a key clinical tool that shows the protein expression of molecular markers. Expression of molecular markers in breast pathology has been used to distinguish breast cancers from benign lesions, classify subtypes of breast cancers, and determine therapeutic intervention. It is a relatively fast and efficient option in stratifying breast lesions to assist in both determining pathology diagnosis and offer strategies to the best course of clinical action. In this chapter, we discuss the use of immunohistochemistry testing for some of the key molecular markers involved in breast pathology that are crucial for classifying breast cancers and the guidelines for the interpretation of testing results that assist in clinical management.